Human erythrocyte superoxide dismutase in adults, neonates, and normal, hypoxaemic, anaemic, and chromosomally abnormal fetuses

Dynamics of cytokines predicts risk of hepatocellular carcinoma among chronic hepatitis C patients after viral eradication

BACKGROUND

Chronic hepatitis C virus (HCV) infection induces profound alterations in the cytokine and chemokine signatures in peripheral blood. Clearance of HCV by antivirals results in host immune modification, which may interfere with immune-mediated cancer surveillance. Identifying HCV patients who remain at risk of hepatocellular carcinoma (HCC) following HCV eradication remains an unmet need. We hypothesized that antiviral therapy-induced immune reconstruction may be relevant to HCC development.

AIM

To investigate the impact of differential dynamics of cytokine expression on the development of HCC following successful antiviral therapy.

METHODS

One hundred treatment-naïve HCV patients with advanced fibrosis (F3/4) treated with direct-acting antivirals (DAAs) or peginterferon/ribavirin who achieved sustained virologic response [SVR, defined as undetectable HCV RNA throughout 12 wk (SVR12) for the DAA group or 24 wk (SVR24) for the interferon group after completion of antiviral therapy] were enrolled since 2003. The primary endpoint was the development of new-onset HCC. Standard HCC surveillance (abdominal ultrasound and α-fetoprotein) was performed every six months during the follow-up. Overall, 64 serum cytokines were detected by the multiplex immunoassay at baseline and 24 wk after end-of-treatment.

RESULTS

HCC developed in 12 of the 97 patients over 459 person-years after HCV eradication. In univariate analysis, the Fibrosis-4 index (FIB-4), hemoglobin A1c (HbA1c), the dynamics of tumor necrosis factor-α (TNF-α), and TNF-like weak inducer of apoptosis (TWEAK) after antiviral therapy were significant HCC predictors. The multivariate Cox regression model showed that ΔTNF-α (≤ -5.7 pg/mL) was the most important risk factor for HCC (HR = 11.54, 95%CI: 2.27-58.72, P = 0.003 in overall cases; HR = 9.98, 95%CI: 1.88-52.87, P = 0.007 in the interferon group). An HCC predictive model comprising FIB-4, HbA1c, ΔTNF-α, and ΔTWEAK had excellent performance, with 3-, 5-, 10-, and 13-year areas under the curve of 0.882, 0.864, 0.903, and 1.000, respectively. The 5-year accumulative risks of HCC were 0%, 16.9%, and 40.0% in the low-, intermediate-, and high-risk groups, respectively.

CONCLUSION

Downregulation of serum TNF-α significantly increases the risk of HCC after HCV eradication. A predictive model consisting of cytokine kinetics could ameliorate personalized HCC surveillance strategies for post-SVR HCV patients.

Oxidative Stress and Antioxidant Enzyme Activities in Newborns with Oesophageal Atresia and Their Mothers

OBJECTIVE: To measure the oxidant/antioxidant status of newborn babies with oesophageal atresia and their mothers, compared with healthy control subjects. METHODS: This case—control study included 40 participants: 10 newborns with oesophageal atresia and their mothers, and 10 healthy newborns and their mothers. Whole blood malondialdehyde (MDA) levels and the activities of antioxidant enzymes (catalase, carbonic anhydrase [CA], glucose-6-phosphate dehydrogenase [G-6-PD], and superoxide dismutase [SOD]) were measured. RESULTS: MDA levels and CA activity were significantly higher, and catalase, SOD and G-6-PD activities were significantly lower, in newborns with oesophageal atresia and their mothers than in healthy newborns and their mothers. Although CA activity was similar between the newborns and mothers in the patient group, it was significantly lower in newborns than in mothers in the healthy group. CONCLUSIONS: Increased lipid peroxidation might play an important role in the pathogenesis of oesophageal atresia. Impairment of the free radical/antioxidant balance may lead to increased free radical and decreased antioxidant levels in oesophageal atresia.

The exercise redox paradigm in the Down's syndrome: improvements in motor function and increases in blood oxidative status in young adults

Considerable evidence has indicated a pro-oxidant status in the brain of people with Down's syndrome (DS), which may contribute to motor and cognitive impairments verified in this condition. On the other hand, previous studies addressing the role of physical exercise on oxidative stress and antioxidant status in DS have indicated conflicting results. Here, we investigated the effects of a supervised judo training of controlled intensity and monitored on the basis of lactate threshold on the blood oxidative stress status and motor coordination in 21 young adults with DS. The training extended over a period of 16 weeks and consisted of three sessions per week. The exercise improved the motor function and significantly decreased lactate production in the DS subjects. However, blood markers of oxidative damage to lipids (TBARS and lipid peroxides) and proteins (carbonyls) were increased by the judo training. Moreover, superoxide dismutase and catalase activity also increased, while glutathione peroxidase activity remained unaltered after exercise. These results reinforce the notion that physical exercise can improve motor disabilities in people with DS. More importantly, our findings demonstrate that the beneficial effects are accompanied by some degree of oxidative stress, suggesting that young adults with DS may be more susceptible to physical training-induced oxidative stress than adolescents with DS, which should be taken into account in physical training programs for this population.

First trimester ultrasonography in screening and detection of fetal anomalies

An obstetrical ultrasound examination provides invaluable information regarding the fetus. Until the mid-1980s, ultrasound in the first trimester was limited to localization of the pregnancy, establishing viability, and accurate dating. With the advent of high-resolution ultrasound and transvaginal scanning, a significant amount of information about the fetus can be gained and provided to the patient at a very early stage in gestation. This article provides an overview of the role of first trimester (11-13 + 6 weeks' gestation) ultrasound in screening and diagnosis of fetal anomalies. The first trimester is an ideal time for screening for aneuploidy, primarily due to the advantages that nuchal translucency (NT) measurement provides. NT measurement is also useful in establishing the risk of congenital cardiac disorders and a number of genetic and non-genetic syndromes. Significant NT thickening is associated with an increase in perinatal morbidity and mortality. Potential mechanisms resulting in increased NT are discussed. A number of new ultrasound markers for fetal aneuploidy have been investigated over the past several years, some of which appear to improve the screening efficacy of early ultrasonography. The role of these is reviewed. A number of fetal anomalies can now be consistently diagnosed in the first trimester. Their appearance at this early gestational age is discussed as well. It is clear that, data obtained by first trimester ultrasound are useful in counseling expectant parents and in planning the appropriate follow-up.

Erythrocyte Cu/Zn Superoxide Dismutase Activity in Preterm Infants with and without Bronchopulmonary Dysplasia

BACKGROUND

Erythrocyte Cu/Zn superoxide dismutase is believed to play a major role as a first-line antioxidant defense. Studies have reported varying results from measures of superoxide dismutase activity in cord blood samples from neonates.

OBJECTIVE

The study goal was to assess enzyme activity for preterm infants representing a range of gestational ages during the 1st week of life. Clinical data were obtained and correlations with superoxide dismutase activity were examined.

METHODS

We collected blood samples from umbilical arterial lines or the radial artery of 44 preterm infants (gestational age range 25-30 weeks) on days 1, 3, and 6 after delivery and evaluated erythrocyte Cu/Zn superoxide dismutase activity.

RESULTS

There was no correlation between enzyme activity and gestational age or birth weight. Superoxide dismutase activity gradually increased in preterm infants with bronchopulmonary dysplasia on days 3 and 6, with levels significantly higher than those of preterm infants without bronchopulmonary dysplasia on day 6. We found that packed red cell transfusion did not affect erythrocyte superoxide dismutase activity in either group. However, higher cumulative oxygen administration was noted in preterm infants with bronchopulmonary dysplasia.

CONCLUSION

Higher cumulative oxygen administration may be one factor that upregulates the activity of erythrocyte superoxide dismutase.

Measurement of Cu/Zn SOD in placenta, cultured cells, various fetal tissues, decidua and semen by ELISA

The concentration of copper/zinc-containing superoxide dismutase (Cu/Zn SOD) was measured in placental villous tissues (8-20 weeks' gestation), decidual tissues, cultured cells from chorionic villi and amniotic fluid cells, various fetal tissues (8-11 weeks' gestation), spermatozoa, seminal plasma and ovarian follicular fluid using a sensitive enzyme-linked immunosorbent assay (ELISA). The isoenzyme was expressed in all samples expect ovarian follicular fluid. Cu/Zn SOD was also detected in hydatidiform mole and choriocarcinoma. In placental villous tissues the concentration of the enzyme increased with gestation between 8 and 20 weeks of pregnancy (n = 69, r = 0.34, P < 0.005).

Increased nuchal translucency with normal karyotype

Increased fetal nuchal translucency (NT) thickness between 11 and 14 weeks' gestation is a common phenotypic expression of chromosomal abnormalities, including trisomy 21. However, even in the absence of aneuploidy, nuchal thickening is clinically relevant because it is associated with an increase in adverse perinatal outcome caused by a variety of fetal malformations, dysplasias, deformations, dysruptions, and genetic syndromes. Once the presence of aneuploidy is ruled out, the risk of perinatal outcome dose not statistically increase until the nuchal translucency measurement reaches 3.5 mm or more (>99th percentile). This increase in risk occurs in an exponential fashion as the NT measurement increases. However, if the fetus survives until midgestation, and if a targeted ultrasound at 20 to 22 weeks fails to reveal any abnormalities, the risk of an adverse perinatal outcome and postnatal developmental delay is not statistically increased.

Malondialdehyde: a possible marker of ageing

BACKGROUND

Numerous recent studies have suggested that oxidative damage may be important in the ageing process, and lipid peroxidation is an important biological consequence of oxidative cellular damage.

OBJECTIVE

The aim of this work was to analyze the activities of the two protective enzymes, superoxide dismutase (SOD) and catalase (CAT), and the levels of malondialdehyde (MDA) to examine the relationship between the ageing process and defence antioxidant and lipid peroxidation.

METHOD

SOD activity was measured in red blood cells using the Minami and Yoshikawa method; CAT activity was measured in hemolysates by the Aebi method, and MDA levels were measured in erythrocytes by high-performance liquid chromatography.

RESULTS

SOD activity shows statistically significant differences between newborns and the rest of the sample (ANOVA p < 0.001; Student-Newman-Keuls test p < 0.001). CAT activity did not show significant differences between the age groups. We observed statistically significant differences in MDA levels between the different groups (ANOVA p < 0.001; Student-Newman-Keuls test p < 0.05). In the regression analysis and rectilinear/curvilinear adjustment compared to age, SOD and CAT showed coefficients close to zero (SOD linear = 0.16; SOD exponential = 0.15; CAT linear = 0.056; CAT exponential = 0.068), indicating in that way their independence from age. Only MDA obtained a regression coefficient superior to 0.75 (p < 0.05). The best adjustment was reached through an exponential expression, giving the following parametric relation: MDA = 103.117e(0.0021.AGE). No statistically significant variation in SOD and CAT activity and MDA levels, related to sex could be demonstrated.

CONCLUSIONS

Our data show that old age is associated with an increase in systemic oxidative stress.

Effects of donor age on the expression of a marker of replicative senescence (EPC-1) in human dermal fibroblasts

EPC-1 (early population doubling level cDNA-1) is a quiescence-specific gene expressed at high levels by early passage WI-38 fibroblasts under conditions of either density-dependent growth arrest or serum deprivation. Late passage WI-38 cells lose the ability to express EPC-1 under all conditions tested. The decline in EPC-1 mRNA is gradual during the replicative life span and correlates inversely with the population doubling level (PDL) of the cells. The objective of this study was to determine whether the decline in EPC-7 mRNA abundance observed during proliferative senescence also occurs in cultures derived from donors of different ages. To address this question, we examined the abundance of EPC-1 mRNA in 28 skin fibroblast lines established from healthy donors of different ages ranging from 12 fetal weeks to 94 years. EPC-1 expression was measured, under conditions of growth arrest, prior to the end of the replicative life span of the cultures. Despite some variability in steady-state transcript levels among the cell lines, EPC-1 expression was significantly lower in cells derived from the fetal donor group (12-20 gestational weeks) than in cells derived from adult donors. An in vitro age-dependent decline in EPC-1 expression was observed in all the skin lines examined, independent of donor age; however, no significant difference was observed between the young adult donor group (17-33 years) and the old adult donor group (78-94 years). Thus, expression of EPC-1 is linked to the replicative age of the cells and whether the cells are derived from fetal skin or adult skin. In adults, EPC-1 expression is independent of donor age.

Oxidative stress and superoxide dismutase in development, aging and gene regulation

Free radicals and other reactive oxygen species are produced in the metabolic pathways of aerobic cells and affect a number of biological processes. Oxidation reactions have been postulated to play a role in aging, a number of degenerative diseases, differentiation and development as well as serving as subcellular messengers in gene regulatory and signal transduction pathways. The discovery of the activity of superoxide dismutase is a seminal work in free radical biology, because it established that free radicals were generated by cells and because it made removal of a specific free radical substance possible for the first time, which greatly accelerated research in this area. In this review, the role of reactive oxygen in aging, amyotrophic lateral sclerosis (a neurodegenerative disease), development, differentiation, and signal transduction are discussed. Emphasis is also given to the role of superoxide dismutases in these phenomena.

Expression and regulation of superoxide dismutase activity in human skin fibroblasts from donors of different ages

We have determined the activities, protein, and mRNA abundances as well as the level of transcriptional activation of two intracellular forms of the free radical metabolizing enzyme superoxide dismutase in 29 human skin fibroblast lines established from donors of different ages. SOD-1 (a copper and zinc containing form of SOD) and SOD-2 (a manganese containing form of the enzyme) activities were both observed to be significantly lower in cell lines derived from fetal skin than in lines established from postnatal skin (ages 17-94 years). The percent of total activity contributed by SOD-1 decreased in an age-associated manner from approximately 50% in the fetal lines to less than 20% in lines established from old tissue donors. All of the cell lines were screened to exclude the possibility that they contained a polymorphism known to influence SOD-2 activity. Northern blot analysis revealed three SOD-1 mRNA transcripts that were 0.5, 0.7, and 1.9 kb in length. Although SOD-1 protein abundance was lower in fetal lines than in lines derived from postnatal donors, SOD-1 mRNA abundance did not differ between fetal cells and cell lines derived from young donors. SOD-2 protein abundance and mRNA abundance were both significantly lower in fetal lines than in postnatal lines. No postnatal age-dependent differences were observed in any of the SOD-2 parameters examined. Nuclear run-on analysis revealed that fetal cell lines exhibited a lower level of transcriptional initiation for SOD-1 than postnatal lines. The transcription of SOD-2 was readily detected in postnatal lines, but undetectable in fetal lines. These results are consistent with multiple levels of control for SOD-1 expression and with a strong transcriptional influence on SOD-2 expression.